Extensive fibrosis in mediastinal seminoma is a diagnostic pitfall in small biopsies: two case reports.
Mediastinal
case report
regression
seminoma
Journal
Mediastinum (Hong Kong, China)
ISSN: 2522-6711
Titre abrégé: Mediastinum
Pays: China
ID NLM: 101731833
Informations de publication
Date de publication:
2023
2023
Historique:
received:
31
03
2022
accepted:
29
07
2022
entrez:
17
3
2023
pubmed:
18
3
2023
medline:
18
3
2023
Statut:
epublish
Résumé
In mediastinal biopsies that show fibrosis, the differential diagnosis includes fibrosing mediastinitis, immunoglobulin G subclass 4-related disease, Hodgkin lymphoma, as well as reactive fibrotic and inflammatory changes adjacent to other processes including neoplasms. We report two cases of incidentally detected mediastinal seminoma that contained extensive areas of paucicellular fibrosis, which precluded accurate preoperative biopsy diagnosis. The fibrosis consisted of mildly inflamed, densely scarred tissue with thin dilated vessels, and was present to a significant extent that is suggestive of spontaneous regression. These features are not currently described in the World Health Organization Classification of Thoracic Tumors. In both patients, needle and open biopsies sampled only the fibrotic areas of the tumors, and the final diagnosis was not achieved until surgical excision was performed. After surgery, both patients received chemotherapy, and were alive without evidence of disease at 3.4 years and 1 year post-operatively, respectively. Tumor fibrosis composed approximately 95% and 50% of each patient's tumor, respectively. In one of the patients, correlation of the needle biopsy position with the positron emission tomography (PET) scan revealed that the biopsy needle had sampled a non-metabolically active portion of the tumor. While pathologic spontaneous regression is well-described in gonadal germ cell tumors, it is not well-reported in extragonadal locations. Prospective knowledge of this diagnostic pitfall and targeting PET-avid regions of the tumor may increase the diagnostic yield and help to avoid non-indicated surgical interventions.
Sections du résumé
Background
UNASSIGNED
In mediastinal biopsies that show fibrosis, the differential diagnosis includes fibrosing mediastinitis, immunoglobulin G subclass 4-related disease, Hodgkin lymphoma, as well as reactive fibrotic and inflammatory changes adjacent to other processes including neoplasms.
Cases Description
UNASSIGNED
We report two cases of incidentally detected mediastinal seminoma that contained extensive areas of paucicellular fibrosis, which precluded accurate preoperative biopsy diagnosis. The fibrosis consisted of mildly inflamed, densely scarred tissue with thin dilated vessels, and was present to a significant extent that is suggestive of spontaneous regression. These features are not currently described in the World Health Organization Classification of Thoracic Tumors. In both patients, needle and open biopsies sampled only the fibrotic areas of the tumors, and the final diagnosis was not achieved until surgical excision was performed. After surgery, both patients received chemotherapy, and were alive without evidence of disease at 3.4 years and 1 year post-operatively, respectively. Tumor fibrosis composed approximately 95% and 50% of each patient's tumor, respectively. In one of the patients, correlation of the needle biopsy position with the positron emission tomography (PET) scan revealed that the biopsy needle had sampled a non-metabolically active portion of the tumor.
Conclusions
UNASSIGNED
While pathologic spontaneous regression is well-described in gonadal germ cell tumors, it is not well-reported in extragonadal locations. Prospective knowledge of this diagnostic pitfall and targeting PET-avid regions of the tumor may increase the diagnostic yield and help to avoid non-indicated surgical interventions.
Identifiants
pubmed: 36926291
doi: 10.21037/med-22-15
pii: med-07-6
pmc: PMC10011866
doi:
Types de publication
Case Reports
Langues
eng
Pagination
6Informations de copyright
2023 Mediastinum. All rights reserved.
Déclaration de conflit d'intérêts
Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at https://med.amegroups.com/article/view/10.21037/med-22-15/coif). The authors have no conflicts of interest to declare.
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